Projectile motion

Conceptual Physics, HewittChapter 3: Projectile Motion

Questions About Projectile Motion

1)

Which of the following is not a vector quantity? A)

velocity B)

speed C)

acceleration D)

None are vector quantities. E)

All are vector quantities. Answer:

B Diff: 1 Topic: Projectile Motion

2)

An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of A)

0 km/h. B)

100 km/h. C)

141 km/h. D)

200 km/h. Answer:

C Diff: 1 Topic: Projectile Motion

3)

An airplane travels at 141 km/h toward the northeast. What is its component of velocity due north? A)

41 km/h

B)

100 km/h C)

110 km/h D)

141 km/h Answer:


Figure 10-B

4)

A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, its vertical component of velocity

A)

increases. B)

remains unchanged. C)

decreases. Answer:


5)

A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, its horizontal component of velocity

A)

increases. B)

remains unchanged. C)

decreases. Answer:


6)

A stone is thrown horizontally from the top of a cliff. One second after it has left your hand its vertical distance below the top of the cliff is

A)

5 m. B)

10 m. C)

15 m. Answer:

A Diff: 1 Topic: Projectile Motion

7)

Throw an object upward at a 45 degree angle. With no gravity it will follow a straight-line path. But because of gravity, at the end of 1 second, it is

A)

about 5 m below the straight line. B)

about 10 m below the straight line. C)

about 15 m below the straight line. Answer:


8)

Roll a bowling ball off the edge of a table. As it falls, its horizontal component of velocity A)

decreases. B)

remains constant. C)

increases. Answer:


9)

A bullet fired horizontally from a rifle begins to fall A)

as soon as it leaves the barrel. B)

after air friction reduces its speed. C)

neither of these Answer:


10)

A projectile is launched vertically upward at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is

A)

less than 50 m/s. B)

50 m/s. C)

more than 50 m/s. Answer:


11)

An Earth satellite is simply a projectile A)

freely falling around the earth. B)

floating motionless in space near the earth. C)

approaching the earth from outer space. Answer:


12)

Earth satellites are typically more than 100 km high so as to be above the Earth's A)

atmosphere. B)

gravitational field. C)

both of these Answer:


13)

A projectile is fired horizontally in a region of no air resistance. The projectile maintains its horizontal component of velocity because

A)

it is not acted on by any forces. B)

it is not acted on by any horizontal forces. C)

it has no vertical component of velocity to begin with. D)

the net force acting on it is zero. E)

none of these Answer:


14)

A hunter on level ground fires a bullet at an angle of 10 degrees above the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?

A)

the dropped one B)

the fired one C)

Both hit at the same time. Answer:


15)

A hunter on level ground fires a bullet at an angle of 2 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?

A)

the dropped one B)

the fired one C)

Both hit at the same time. Answer:


16)

A bullet fired horizontally over level ground hits the ground in 0.5 second. If it had been fired with twice the speed in the same direction, it would have hit the ground in

A)

less than 0.5 s. B)

more than 0.5 s. C)

0.5 s. Answer:


17)

An object is dropped and freely falls to the ground with an acceleration of 1 g. If it is thrown upward at an angle instead, its acceleration will be

A)

0 g. B)

1 g downward. C)

1 g upward. D)

larger than 1 g. E)



20)

A gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. Neglecting air resistance, how far downrange will the bullet be 1 second later?

A)

50 m B)

98 C)

100 D)

490 E)



22)

After a rock thrown straight up reaches the top of its path and then falls a short distance, its acceleration is (neglect air resistance)

A)

greater than when it was a the top of its path. B)

less than when it was at the top of its path. C)

the same as it was at the top of its path. Answer:


23)

What prevents satellites such as a space shuttle from falling? A)

gravity B)

the absence of air drag C)

Nothing; they're falling continuously all around the Earth. Answer:


25)

The ground speed of an airplane that has an airspeed of 200 km/h when it is in a 200-km/h crosswind is A)

0 km/h. B)

200 km/h. C)

283 km/h. D)

400 km/h. E)

1600 km/h. Answer:


29)

A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The player sees the ball land 20 m down range. What is the player's pitching speed?

A)

about 5 m/s B)

about 10 m/s C)

about 20 m/s D)

about 25 m/s E)



30)

An airplane flies at 40 m/s at an altitude of 50 meters. The pilot drops a heavy package which falls to the ground. Where, approximately, does the package land relative to the plane's new position?

A)

beneath the plane B)

400 m behind the plane C)

500 m behind the plane D)

more than 500 m behind the plane E)



31)

A bullet is fired horizontally with an initial velocity of 300 m/s from a tower 20 m high. If air resistance is negligible, the horizontal distance the bullet travels before hitting the ground is about

A)

200 m. B)

300 m. C)

400 m. D)

500 m. E)

600 m. Answer:

E Diff: 3 Topic: Projectile Motion

32)

A river 100 m wide flows due south at 1 m/s. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat reaches the east bank

A)

due east of where it started. B)

141 m farther south than where it started. C)

100 m farther south than where it started. D)

100 m farther north than where it started. Answer:

C Diff: 3 Topic: Adding Vectors

33)

A river 100 m wide flows due south. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. Relative to the Earth, the boat travels

A)

nowhere. B)

141 m. C)

100 m. D)

200 m. E)

241 m. Answer:

B Diff: 3 Topic: Adding Vectors

34)

A river 100 m wide flows due south. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat crosses in

A)

50 s. B)

100 s. C)

141 s. D)

200 s. Answer:

B Diff: 3 Topic: Adding Vectors

35)

A river 100 m wide flows due south at 1 m/s. A boat that goes 1 m/s relative to the water leaves the west bank. To land at a point due east of its starting point, the boat must be pointed

A)

northeast. B)

east. C)

southeast. D)

Nowhere: it can't be done.

Answer:

D Diff: 5 Topic: Adding Vectors

Projectile motion

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